A dental treatment often begins with obtaining a three-dimensional (3D) model of a patient's teeth. The model may be a physical model of the dentition or a virtual 3D computer model. The model is used to assist in designing a dental treatment for the patient. After the treatment has been designed, the model is used to design the dental prosthesis or appliance to be applied to the teeth in order to execute the treatment. Such prostheses and appliances include, for example, bridges, crowns, and orthodontic braces.
In some instances, a negative cast of the dentition is obtained at the dental clinic in which the patient is seen, and may include both arches, one arch, or part of an arch. The cast is sent to a dental laboratory, and a positive physical model of the dentition is made from the negative cast, typically by pouring plaster into the cast allowing the plaster to set. A dental treatment is then determined at the clinic using the model, and prostheses or appliances for mounting onto the patient's teeth are designed or selected in order to execute the treatment. The appliances are made at a laboratory and then dispatched to the clinic for mounting onto the patient's teeth.
It is also known to obtain a 3D virtual representation of the teeth that is used to assist in devising a dental treatment and/or to design dental appliances. The 3D computer model may be obtained at the dental clinic using an optical scanner to scan the teeth directly or to scan a model of the teeth. The computer model is then used at the clinic for designing or selecting appropriate dental prosthesis and/or appliances to carry out the treatment. Instructions are then sent to a dental appliance laboratory for making the prosthesis or appliances, which are made at the laboratory and then dispatched to the clinic.
Alternatively, a negative cast of the dentition of each jaw is obtained at a dental clinic that is dispatched to a dental appliance laboratory where a 3D positive model of the patient's teeth is made from the negative cast. The 3D model is then scanned at the laboratory so as to generate a virtual 3D model of the patient's teeth that is used to design appropriate dental prosthesis or appliances. The prosthesis or appliances are produced at the laboratory and then dispatched to the clinic.
U.S. Pat. No. 6,632,089 to Rubbert et al., discloses a computer-based dental treatment planning method. A virtual 3D model of the dentition of a patient is obtained that is used to plan a dental treatment. Obtaining the 3D model as well as treatment planning can be performed at a dental clinic or at a remote location such as a dental appliance laboratory having access to the virtual model of the dentition. In the latter situation, the proposed treatment plan is sent to the clinic for review, and modification or approval by the dentist, before the requisite appliances are made at the laboratory.